This invention relates to natural compositions and methods that both repel head lice and treat pediculosis capitis. 
Head lice infestation (pediculosis capitis) is a major problem in the United States, throughout Europe and Asia. In the United States alone 10 million cases of pediculosis capitis occurred in 1989. Lice are external parasites of warm blooded animals. They spread by crowding and sharing of personal items such as combs, hats, brushes and clothing.
Humans are host to three different types of lice, 1) head lice, 2) body lice, 3) crab or pubic lice.
The head louse has been among humans since their earliest origins. The louse has evolved in a highly specialized manner for survival on the haired human scalp, to the extent that its survival requires it to spend its entire life-cycle on a human host.
The life cycle of the head louse falls into three phases, egg, nymph and mature louse.
Louse eggs, some 0.5 to 0.8 by 0.3 millimeters, are usually laid at the base of hairs, within 0.5 mill of the scalp, where they hatch after seven or eight days. During incubation, the hair will grow away from the scalp by some two millimeters. The eggs are firmly glued to the hair, usually one per hair, by a clear, quick-setting substance secreted by the female. Live eggs are usually camouflaged by being the same color as the scalp.
The nymph resembles the adult louse in behavior, and in physical terms apart from size. In about ten days after hatching it is mature.
Mature head lice are 2 to 4 millimeters long, shun light, and move swiftlyxe2x80x9410 to 20 centimeters a minutexe2x80x94in all lateral directions, clinging to and crawling through the hair with their six claws. Otherwise transparent, head lice camouflage themselves by darkening, after feeding, to the color of the skin and hair of the host, in the range from blond to black.
The empty egg-shell is called a nit. It is white in color, and remains firmly glued to the hair. The hair grows at a rate of some one centimeter per month, carrying any nits attached to it away from the scalp.
The characteristic feature of the group to which human head-lice belong is blood-sucking. To feed, the louse pierces the scalp with its mouth-parts, pumping in saliva and drawing out a mixture of saliva and blood. While humans are not born with the ability to react to such bites, repeated contact with the sensitizing allergens contained in the saliva creates an allergic reaction, so that each further bite evokes an itchy reaction. Wounds produced in the scalp by scratching in response to itches can become inflamed and infected. If louse infestation is allowed to persist, the wounds can develop an extreme condition, wherein successful treatment cannot be assured.
A population of head lice which is neglected will reach a steady state, where the death-rate equals the birth-rate, and some two hundred lice of all post-ovum stages are present. About five thousand eggs are laid each month and the head eventually becomes grey with drifts of empty egg shells. Such a population, when present for some months, is enough to produce the symptoms of pediculosis capitis. The child becomes itchy, tired, dull and sullen. The bright child becomes average, and the average child stupid.
Although they can be shown to act as transmitters of typhus and fevers in the laboratory, head lice are not responsible for the transmission of disease in the field. Lice are considered highly unlikely to transmit AIDS.
The highest incidence of pediculosis capitis is found in children between the ages of five and fifteen years. In the developed world head lice are most prevalent among suburban and rural children.
Even though people experience unpleasant sensations as a result of louse infestation, they often deny pediculosis capitis because of feelings of disgust and shame. Lice infestation used to be thought of as a problem only of the poor or poorly housed. It is now abundantly clear that the problem of head lice has extended to a very large number of middle class homes in the western world and this leads to increasing numbers of consultations with family practitioners or pharmacists who advise as to the treatment currently being recommended.
Other general recommendations include machine washing in hot water (over 54xc2x0 C.) or dry cleaning all clothing, including coats, hats, scarves, pillow cases, towels, and bedding materials, which may have contacted an infested individual.
Several products for treating pediculosis capitis are available over the counter, the most widely used products in this category include Rid(copyright) Lice Killing Shampoo (Pfizer), Nix(copyright) Cream Rinse and A-2000(copyright) Shampoo Concentrate which contains pyrethins and piperonyl butoxide as active ingredients. Prescription drugs include Ovidem(copyright) (active ingredient 0.5% malathion) and Kwell(copyright) (containing landane 1%).
Pediculicides, selectively kill lice which invade the epidermis. Although a number of brands contain either carbaryl or malathion, lotions containing phenothrin and permethrin are now the major products. These are pyrethroid compounds are highly effective insecticidal neurotoxins, with efficacy against both adult lice and their eggs. Permethrin (3-phenoxyphenyl)methyl (+/xe2x88x92) cis/trans 3-(2,2-dichloroethenyl)2,2-dimethylcyclopropanecarboxylate, is used as a 0.5% preparation in a paraffin base. Other actives are benzyl benzoate and crotamiton. All are applied topically. The manufacturers claim appropriate use does not lead to resistance but evidence now would seem to suggest otherwise. Many health authorities are now advising no active treatment because of problems apparently due to resistant lice. Instead they recommend over-conditioning the hair and regular use of a specially designed lice comb.
It is clear that a repellent, which curtails infestation, is preferable. A number of insect repellents have been developed, however most are not specific for lice. Several natural repellents are specific for mosquitoes or fleas, U.S. Pat. No. 5,106,622 teaches a natural repellent effective against mosquitoes and ticks, U.S. Pat. No. 5,738,863 teaches a honey bee repellent comprising tea tree oil, U.S. Pat. No. 5,411,992 teaches a lice repellent comprising terpenoids. This survey shows that there is no teaching of the invention, which is a topical, natural composition useful as both a lice repellent and a treatment of pediculosis capitis. 
The following U.S. patents are considered relevant:
U.S. Pat. No. 4,193,986
U.S. Pat. No. 4,587,123
U.S. Pat. No. 5,591,435
U.S. Pat. No. 4,927,813
U.S. Pat. No. 5,411,992
U.S. Pat. No. 4,759,930
U.S. Pat. No. 5,208,029
U.S. Pat. No. 4,933,371
U.S. Pat. No. 4,193,986
U.S. Pat. No. 5,783,863
U.S. Pat. No. 4,379,168
U.S. Pat. No. 5,106,622
It has been discovered that the combination of three essential oils: anise, tea tree and lemon, in a concentration of between 0.01% and 50%, most preferably between 0.01% and 10%, is a very good head lice repellent and treatment of pediculosis capitis. 
The active agent can be combined with a pharmaceutically and/or cosmetically acceptable carrier for topical administration, such as an aqueous or alcohol solution, a gel, or cream, and administered with or without additives such as preservatives, antioxidents, fragrances, agents increasing solubility or delaying release of active agents.
The active agent in concentrated form can be added to personal preference shampoos, hair-sprays, rinses, styling gel or other personal preference hair care products.
The active agent can also be used to treat material such as hairbows, headbands, caps, hats, helmet linings, any object that is made of cloth and worn on the head.
The active agent can also be used as a head lice repellent and treatment of pediculosis capitis for animals.
Other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It is to be understood however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.
Accordingly, besides the objects and advantages of the compositions and methods described in this patent, several objects and advantages of the present invention are:
a) To provide a novel, low cost, combination head lice repellent and treatment of pediculosis capitis. 
b) To provide a natural, non-toxic head lice repellent and treatment of pediculosis capitis desirable for health and environmental concerns.
c) To provide a non-irritating head lice repellent and treatment of pediculosis capitis. 
d) To fill a market void by offering a head lice repellent that has the potential to curtail epidemics of pediculosis capitis. 
e) To provide an easy-to-use head lice repellent and treatment of pediculosis capitis. 
f) To eliminate, by the use of the repellent, the need to purchase additional costly products and extend considerable effort exterminating lice and nits from bedding, clothing, furnishings, etc.
g) To provide a head lice repellent that does not kill insects, thus, populations of target insects will not select as readily for resistance to the repellent.
h) To provide a novel method of utilizing a head lice repellent.
i) To provide a head lice repellent and treatment for pediculosis capitis in concentrate form that can be easily combined with the users personal preference of hair care products.
Natural anise oil is an essential oil of the family ammiaceae (carrot family), anise (pimpinella anisum) is a herb having a strong odor and bearing seeds from which is distilled the aromatic oil of anise. The flavoring is used in liqueurs and some bakery products and confections. It is non-toxic and non-irritating to the skin. See, Van Nostrands Scientific Encyclopedia 5th Edition P.156.
Natural tea tree oil is an essential oil of the tea tree, melaleuca alternifolia, which is native to eastern Australia. It is non-irritating to the skin and non-toxic. Tea tree oil has long been known as being useful as, for example, a machine cutting oil, perfumery toner, flavoring and antiseptic agent and antimicrobial agent. See, e.g., Brophy et al., J. Agric. Food Chem. 37:5, pp. 1330-35 (1989) (Analysis of the tea tree oil); Olsen, Australian Tea Tree Oil (Kali Press 1989).
Natural lemon oil is an essential oil of the rutaceae family. A small evergreen tree, native to Asia, but has become naturalized in the Mediterranean region. It is cultivated in many parts of the world, with most of the oil being produced in Italy, Cyprus, Israel and California. The oil is extracted from cold compression of the peel of the fruit. The aroma is fresh and sharp just like the fresh fruit. Lemon oil has the following properties: anti-anaemic, antimicrobial, anti-rheumatic, antiseptic, antispasmodic, antitoxic, astringent, bactericidal, carminative, cytophylactic, cicatrisant, depurative, diuretic, febrifugal, haemostatic, hypotensive, insecticidal, rubefacient, sudorific, tonic, vermifugal. See, Wildwood, C., The Encyclopedia of Aromatherapy, pp 271 (1996).
Surprisingly, it has now been discovered that essential anise oil, essential tea tree oil, and essential lemon oil can be combined to produce a highly effective, non-toxic head lice repellent and pediculosis capitis treatment composition that contains no harsh chemicals, is environmentally friendly, can be applied topically to humans or animals, and repels or kills insects.
Essential anise oil, essential tea tree oil and essential lemon oil are present in the invention in amounts effective to both repel head lice and treat pediculosis capitis. 
Preferably, essential anise oil is present in an amount from about 3.5% to 25%, more preferably about 3.5% to 10% for repellent, and 9% to 20% for treating pediculosis capitis. 
Preferably, essential tea tree oil is present in an amount from about 2.5% to 20%, more preferably about 3.5% to 7% for repellent, and 7% to 20% for treating pediculosis capitis. 
Preferably, essential lemon oil is present in an amount from about 2% to 15%, more preferably about 2% to 7% for repellent, and 4% to 9% for treating pediculosis capitis. 
The essential oils in this invention can be obtained commercially, for example, from Frontier Natural Products Co-op, Norway, Iowa U.S.
Although the SD alcohol contained in the following examples is used as a carrier and not wishing to be bound to any particular theory, I believe it has properties that are active in the treatment of pediculosis capitis contained in this invention.
The head lice repellent and treatment of pediculosis capitis can be prepared in various forms, such as an aqueous solution, an alcohol solution, a cream, a powder, a gel, a rinse, a spray, hair styling mousse, shampoo, and conditioner.
The head lice repellent and treatment of pediculosis capitis can be delivered in various forms, such as a pump, spray mist, an aerosol spray, a rinse, or a pump spray or liquid dip for brushes, combs, and treated material, such as fabric.
Sprays, for example, can be prepared using conventional propellants, such as propane, butane, isobutane, either alone or in various mixtures known to those skilled in the art.
Typical liquid carriers useful in preparing both repellent and treatment according to the invention include water, alcohols, such as methyl, ethyl, propyl and isopropyl alcohol, glycols, ketones, ethers, hydrocarbons, etc. Appropriate amounts of the liquid carrier can be readily determined by those skilled in the art. For example, when alcohols are used as liquid carriers, they can be present in amounts from about 5% to 90%, in particular 10% to 60%.
Exemplary additives useful in the invention include vitamin E, fragrances, emulsifiers, pH adjusting agents, waxes, antimicrobial agents, preservatives, antioxidents, agents increasing solubility or delaying release of active agents, etc.
The formulations according to the invention can safely be applied to the skin of a human or animal, and can be applied to clothing or other porous or non-porous surfaces.